EP3693155A1 - Apparatus and method to tailor fiber distortion in composite parts - Google Patents
Apparatus and method to tailor fiber distortion in composite parts Download PDFInfo
- Publication number
- EP3693155A1 EP3693155A1 EP19217732.7A EP19217732A EP3693155A1 EP 3693155 A1 EP3693155 A1 EP 3693155A1 EP 19217732 A EP19217732 A EP 19217732A EP 3693155 A1 EP3693155 A1 EP 3693155A1
- Authority
- EP
- European Patent Office
- Prior art keywords
- caul plate
- slit
- extends
- composite material
- uncured composite
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
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- 239000002131 composite material Substances 0.000 title claims abstract description 195
- 238000000034 method Methods 0.000 title claims abstract description 27
- 239000000835 fiber Substances 0.000 title description 49
- 210000000569 greater omentum Anatomy 0.000 claims abstract description 195
- 230000008859 change Effects 0.000 claims abstract description 22
- 230000037303 wrinkles Effects 0.000 claims description 11
- 238000010438 heat treatment Methods 0.000 claims description 3
- 230000006835 compression Effects 0.000 description 13
- 238000007906 compression Methods 0.000 description 13
- 238000004519 manufacturing process Methods 0.000 description 7
- 230000001105 regulatory effect Effects 0.000 description 6
- 230000008569 process Effects 0.000 description 4
- 239000011347 resin Substances 0.000 description 3
- 229920005989 resin Polymers 0.000 description 3
- 230000004075 alteration Effects 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 238000010276 construction Methods 0.000 description 1
- 230000001276 controlling effect Effects 0.000 description 1
- 230000003292 diminished effect Effects 0.000 description 1
- 230000000116 mitigating effect Effects 0.000 description 1
- 230000002787 reinforcement Effects 0.000 description 1
- 238000009877 rendering Methods 0.000 description 1
- 239000003381 stabilizer Substances 0.000 description 1
- 239000003351 stiffener Substances 0.000 description 1
Images
Classifications
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C70/00—Shaping composites, i.e. plastics material comprising reinforcements, fillers or preformed parts, e.g. inserts
- B29C70/04—Shaping composites, i.e. plastics material comprising reinforcements, fillers or preformed parts, e.g. inserts comprising reinforcements only, e.g. self-reinforcing plastics
- B29C70/28—Shaping operations therefor
- B29C70/54—Component parts, details or accessories; Auxiliary operations, e.g. feeding or storage of prepregs or SMC after impregnation or during ageing
- B29C70/541—Positioning reinforcements in a mould, e.g. using clamping means for the reinforcement
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C70/00—Shaping composites, i.e. plastics material comprising reinforcements, fillers or preformed parts, e.g. inserts
- B29C70/68—Shaping composites, i.e. plastics material comprising reinforcements, fillers or preformed parts, e.g. inserts by incorporating or moulding on preformed parts, e.g. inserts or layers, e.g. foam blocks
- B29C70/681—Component parts, details or accessories; Auxiliary operations
- B29C70/682—Preformed parts characterised by their structure, e.g. form
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C43/00—Compression moulding, i.e. applying external pressure to flow the moulding material; Apparatus therefor
- B29C43/32—Component parts, details or accessories; Auxiliary operations
- B29C43/36—Moulds for making articles of definite length, i.e. discrete articles
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C70/00—Shaping composites, i.e. plastics material comprising reinforcements, fillers or preformed parts, e.g. inserts
- B29C70/04—Shaping composites, i.e. plastics material comprising reinforcements, fillers or preformed parts, e.g. inserts comprising reinforcements only, e.g. self-reinforcing plastics
- B29C70/28—Shaping operations therefor
- B29C70/40—Shaping or impregnating by compression not applied
- B29C70/42—Shaping or impregnating by compression not applied for producing articles of definite length, i.e. discrete articles
- B29C70/44—Shaping or impregnating by compression not applied for producing articles of definite length, i.e. discrete articles using isostatic pressure, e.g. pressure difference-moulding, vacuum bag-moulding, autoclave-moulding or expanding rubber-moulding
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C70/00—Shaping composites, i.e. plastics material comprising reinforcements, fillers or preformed parts, e.g. inserts
- B29C70/04—Shaping composites, i.e. plastics material comprising reinforcements, fillers or preformed parts, e.g. inserts comprising reinforcements only, e.g. self-reinforcing plastics
- B29C70/28—Shaping operations therefor
- B29C70/40—Shaping or impregnating by compression not applied
- B29C70/42—Shaping or impregnating by compression not applied for producing articles of definite length, i.e. discrete articles
- B29C70/44—Shaping or impregnating by compression not applied for producing articles of definite length, i.e. discrete articles using isostatic pressure, e.g. pressure difference-moulding, vacuum bag-moulding, autoclave-moulding or expanding rubber-moulding
- B29C70/443—Shaping or impregnating by compression not applied for producing articles of definite length, i.e. discrete articles using isostatic pressure, e.g. pressure difference-moulding, vacuum bag-moulding, autoclave-moulding or expanding rubber-moulding and impregnating by vacuum or injection
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C70/00—Shaping composites, i.e. plastics material comprising reinforcements, fillers or preformed parts, e.g. inserts
- B29C70/04—Shaping composites, i.e. plastics material comprising reinforcements, fillers or preformed parts, e.g. inserts comprising reinforcements only, e.g. self-reinforcing plastics
- B29C70/28—Shaping operations therefor
- B29C70/54—Component parts, details or accessories; Auxiliary operations, e.g. feeding or storage of prepregs or SMC after impregnation or during ageing
- B29C70/549—Details of caul plates, e.g. materials or shape
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C70/00—Shaping composites, i.e. plastics material comprising reinforcements, fillers or preformed parts, e.g. inserts
- B29C70/68—Shaping composites, i.e. plastics material comprising reinforcements, fillers or preformed parts, e.g. inserts by incorporating or moulding on preformed parts, e.g. inserts or layers, e.g. foam blocks
- B29C70/78—Moulding material on one side only of the preformed part
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29D—PRODUCING PARTICULAR ARTICLES FROM PLASTICS OR FROM SUBSTANCES IN A PLASTIC STATE
- B29D99/00—Subject matter not provided for in other groups of this subclass
- B29D99/0003—Producing profiled members, e.g. beams
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B64—AIRCRAFT; AVIATION; COSMONAUTICS
- B64C—AEROPLANES; HELICOPTERS
- B64C3/00—Wings
- B64C3/18—Spars; Ribs; Stringers
- B64C3/182—Stringers, longerons
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B64—AIRCRAFT; AVIATION; COSMONAUTICS
- B64C—AEROPLANES; HELICOPTERS
- B64C3/00—Wings
- B64C3/26—Construction, shape, or attachment of separate skins, e.g. panels
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C43/00—Compression moulding, i.e. applying external pressure to flow the moulding material; Apparatus therefor
- B29C43/32—Component parts, details or accessories; Auxiliary operations
- B29C43/36—Moulds for making articles of definite length, i.e. discrete articles
- B29C43/3642—Bags, bleeder sheets or cauls for isostatic pressing
- B29C2043/3655—Pressure transmitters, e.g. caul plates; pressure pads
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29L—INDEXING SCHEME ASSOCIATED WITH SUBCLASS B29C, RELATING TO PARTICULAR ARTICLES
- B29L2031/00—Other particular articles
- B29L2031/30—Vehicles, e.g. ships or aircraft, or body parts thereof
- B29L2031/3076—Aircrafts
- B29L2031/3085—Wings
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
- Y02T50/00—Aeronautics or air transport
- Y02T50/40—Weight reduction
Definitions
- This disclosure relates to fabrication of composite parts, and more particularly to controlling wrinkling in a finished composite part which incurred fiber distortion prior to curing.
- An alteration or distortion of fiber straightness can occur in a number of different ways with respect to a composite part prior to curing.
- Examples of distortion of fibers prior to curing can occur with the composite part experiencing a change in geometry such as the uncured composite part being positioned to extend about a radius of curvature or with the uncured composite part having a ply drop.
- the change of direction of the composite part can impart tension to fibers in a portion of the composite part and can impart compression to another portion of the composite part prior to curing.
- the fibers positioned in compression within the uncured composite part the fibers can be distorted from a straight line alignment and experience bunching of the fibers. With the fibers in a distorted condition, curing of the composite part can result in uncontrolled wrinkling to occur in the cured composite part.
- Wrinkles which appear in a cured composite part can identify locations within the composite part where the fibers have been distorted and where the composite part has diminished strength.
- the fabricator can add additional composite material to the composite part to reinforce the composite part at those wrinkled locations so as to provide additional strength to the composite part.
- This procedure of adding composite material adds time, labor and material cost in fabricating the composite part.
- this procedure of adding composite material adds weight to the finished composite part. Adding weight to the finished composite part, that is used for example in fabricating an aircraft, contributes to additional cost of operation of the aircraft.
- the control of wrinkling of the finished composite part can avoid the need to add composite material to reinforce the strength of the composite part, which can add weight to a structure being fabricated with the composite part such as an aircraft, resulting in additional operational cost and/or can avoid uncontrolled wrinkling in the composite part exceeding engineering specifications and/or regulatory guidelines and being discarded.
- An example includes a caul plate for application onto an uncured composite material which includes a first slit defined by and which extends through and along the caul plate.
- An example includes a method for fabricating a part constructed from an uncured composite material having a geometric change within the uncured composite material, including a step of positioning a caul plate in overlying relationship to the uncured composite material having a geometric change in the uncured composite material, wherein the caul plate includes a first slit defined by and which extends through and along the caul plate.
- Various parts used in the assembly of structures are constructed of composite material, which includes fibers and resin.
- the parts are often subjected to alteration of geometric shape prior to being cured.
- the change in geometric shape of the uncured part results in distortion of straight-lined alignment of the reinforcement fibers within the composite material used in fabricating the part.
- the distortion of the straight-lined alignment of the fibers can occur by way of, for example, dropping of one or more plies in the construction of the composite part or by way of altering the shape of the composite part so as to conform to a shape of another part, such that the composite material is taken out of being positioned in a flat plane.
- Changing the shape of uncured composite material being used in constructing the part by way of example of dropping plies and/or altering the shape of the composite material out of a flat configuration, alters or distorts the straight-lined alignment of the fibers within the uncured composite material from a straight lined orientation.
- the fibers in a portion of the composite material which follows the curvature can become distorted from a straight-lined alignment.
- a portion of the fibers within the composite material can be placed in tension and another portion of the fibers within the composite material can be placed in compression.
- the fibers subjected to compression can become distorted and tend to bunch.
- the cured composite part can develop undesired uncontrolled wrinkles. Should the uncontrolled wrinkling, which is indicative of reduced strength for the finished composite part, exceed engineering specifications and/or regulatory guidelines for wrinkling, additional composite material may need to be added to the part being fabricated or the part may need to be discarded.
- aircraft 10 is an example of a structure having portions of the structure assembled with parts constructed of composite material, wherein the composite parts are subjected to geometric shape change prior to the composite part being cured.
- portions of aircraft 10, which have composite parts which are subjected to geometric shape change prior to being cured include, for example, wings 12, fuselage 14, tail stabilizer 16, tail wings 18 as well as other structural portions of aircraft 10 and as well as other portions of other structures which are assembled utilizing composite parts.
- Wing 12 includes composite skin 20 which has an inner surface 22, as seen in FIG. 3 , which has a contour which requires blade stringer 24 constructed of composite material 48 to change geometry or shape so as to conform to inner surface 22 of composite skin 20.
- Blade stringer 24 conforms to inner surface 22 of composite skin 20 so as to optimize securement of blade stringer 24 to composite skin 20 and to optimize stiffening support of blade stringer 24 to composite skin 20.
- Blade stringer 24 is described herein as an example of a composite part being fabricated wherein the geometry or shape of the composite part is changed prior to curing. Many other configurations of stringers or other composite parts can used so as to describe the teachings of this disclosure.
- Inner surface 22 of composite skin 20 changes elevation or contour of inner surface 22 of composite skin 20 such as with ramp 26 which includes first curvature 28 and second curvature 29.
- First and second curvatures 28, 29 are positioned at opposing ends of ramp 26 in composite skin 20.
- the contour or change in elevation of inner surface 22 of composite skin 20 can occur, for example, with ply drops in composite skin 20 in accommodating load demands on wing 12 and/or for accommodating size of wing 12, as wing 12 extends away from fuselage 14.
- blade stringer 24 In order for blade stringer 24 to conform to inner surface 22 of composite skin 20, the shape of blade stringer 24 is altered prior to cure of blade stringer 24 such that flanges 30 and web 32 of blade stringer 24 follow the contour or curvature of inner surface 22 of composite skin 20 as blade stringer 24 extends along ramp 26.
- ramp 26 of composite skin 20 is seen with first curvature 28 and second curvature 29 of composite skin 20 positioned at opposing ends of ramp 26, as mentioned above.
- Flange 30, of blade stringer 24 shown in FIG. 3 underlies caul plate 46 in FIG. 6 , includes uncured composite material 48 which has fibers 34 which extend along length L of blade stringer 24, as seen in FIGS. 3 and 6 .
- first curvature 28 of ramp 26 of composite skin 20 With respect to first curvature 28 of ramp 26 of composite skin 20, upper portion 38 of fibers 34 in flange 30 are placed in tension extending along first curvature 28 and lower portion 40 of fibers 34 in flange 30 are placed in compression extending along first curvature 28.
- fibers 36 within web 32 which also extend along length L of blade stringer 24, extend along first curvature 28 of composite skin 20 with upper portion 42 of fibers 36 in web 32 placed in tension and with lower portion 44 of fibers 36 in web 32 placed in compression.
- fibers 34 of uncured composite material 48 of flange 30 of blade stringer 24 has upper portion 38 of fibers 34 in flange 30 placed in compression, which extends along second curvature 29, and lower portion 40 of fibers 34 in flange 30 placed in compression, which extends along second curvature 29.
- Fibers 36 within web 32 which extend along second curvature 29 has upper portion 42 of fibers 36 in web 32 placed in compression and lower portion 44 of fibers 36 in web 32 placed in compression.
- Controlled wrinkling in the finished blade stringer 24 optimizes use of the finished composite part with blade stringer 24 conforming to the engineering specifications and regulatory guidelines related to amount and size of permitted wrinkling that is permitted in a finished composite part and also optimizes resulting strength of blade stringer 24.
- Caul plate 46 is positioned onto uncured composite material 48, as seen in FIGS. 3 and 5 , which includes uncured composite material 48 of flange 30 and web 32 of blade stringer 24 in this example for utilization in the curing process of blade stringer 24.
- uncured composite material 48 of a part to be cured such as blade stringer 24
- caul plate 46 and uncured composite material 48 are placed within a vacuum bagging (not shown) and a reduced pressure is applied within the vacuum bagging, as mentioned above, pulling fibers and resin from uncured composite material 48 into slits of caul plate 46 as will be described below.
- each caul plate 46 has a L-shaped configuration and is positioned on opposing sides of uncured composite material 48 of blade stringer 24, as seen in FIG. 5 .
- Other shapes of caul plate(s) 46 can be used for accommodating other shapes of stringers or for other composite parts being fabricated, which have a geometric change of shape distorting fibers from a straight-lined alignment in forming composite parts prior to curing.
- caul plate 46 is used in placing onto uncured composite material 48 for use during the curing process of uncured composite material 48 fabricating a composite part such as blade stringer 24 with controlled wrinkling.
- Caul plate 46 includes first slit 50 defined by and which extends through and along caul plate 46.
- First slit 50 extends through caul plate 46 from surface 52 of caul plate 46, for positioning onto surface 54 of uncured composite material 48.
- First slit 50 extends through caul plate 46 to an opposing surface 56 of caul plate 46, for positioning in facing relationship away from surface 54 of uncured composite material 48, as seen for example in FIG. 5 , with surface 52 of caul plate 46 positioned onto uncured composite material 48.
- At least a portion 58 of surface 52, of caul plate 46, which is positioned onto uncured composite material 48 of flange 30 extends in a linear direction L as seen in FIG. 5 .
- at least a portion 60 of surface 52 of caul plate 46 which is positioned onto uncured composite material 48 of web 32 extends in linear direction L', as seen in FIG. 5 .
- At least a portion 62 of opposing surface 56 of caul plate 46 which is positioned facing away from composite material 48 of flange 30 extends in linear direction L, as seen in FIG.
- At least a portion 64 of opposing surface 56 of caul plate 46 is positioned facing away from uncured composite material 48 of web 32 extends in linear direction L', as also seen in FIG. 5 .
- At least a portion 66 of surface 52 extends in a curvilinear direction C and a portion 68 of opposing surface 56 extends in the curvilinear direction C.
- first slit 50 extends in a linear direction LD along portion 70 of caul plate 46 which extends in this example along flange 30 of blade stringer 24 and extends in a linear direction LD' along portion 72 of caul plate 46, which extends in this example along web 32 of blade stringer 24.
- portions 70 and 72 of caul plate 46 join one another along a curved portion 74 of caul plate 46 as seen in FIG.4 .
- First slit 50 extends through caul plate 46 positioned within portions 70 and 72 of caul plate 46 and within curved portion 74 of caul plate 46, as also seen in FIG. 4 .
- First slit 50 can be made in a variety of width dimensions and length dimensions as needed for forming controlled wrinkles within a composite part being fabricated.
- width dimension W includes for example one hundredth of an inch (0.01 inch) up to and including five hundreds of an inch (0.05 inch).
- Caul plate 46 includes length L and first slit 50 extends in linear direction LD along portion 70 of caul plate 46, for positioning onto uncured composite material 48 for flange 30 of blade stringer 24, extending in a transverse direction relative to length L of caul plate 46 as seen in FIG. 4 .
- first slit 50 extends in linear direction LD' along portion 72 of caul plate 46, for positioning onto uncured composite material 48 for web 32 of blade stringer 24, extending in a transverse direction relative to length L of caul plate 46 as also seen in FIG. 4 .
- caul plate 46 further includes second slit 76 defined by and which extends through and along caul plate 46 positioned spaced apart from first slit 50.
- First slit 50 and second slit 76 extend along caul plate 46 spaced apart from one another and extending in the same direction, and as shown in FIG. 4 , parallel to one another.
- Caul plate 46 includes end 78 and second opposing end 80.
- First slit 50 extends through end 78 of caul plate 46 and extends toward second opposing end 80 of caul plate 46 wherein end 82 of first slit 50 is defined by caul plate 46 positioned spaced apart from second opposing end 80 of caul plate 46.
- Second slit 76 extends through second opposing end 80 of caul plate 46 and extends toward end 78 of caul plate 46 wherein end 84 of second slit 76 is defined by caul plate 46 positioned spaced apart from end 78 of caul plate 46.
- third slit 86 is defined by and extends through and along caul plate 46 is positioned adjacent to second slit 76 with second slit 76 positioned between first slit 50 and third slit 86.
- Third slit 86 extends through end 78 of caul plate 46 toward second opposing end 80 of caul plate 46.
- End 88 of third slit 86 is defined by caul plate 46 positioned spaced apart from second opposing end 80 of caul plate 46.
- Fourth slit 90 is defined by and extends through and along caul plate 46 positioned adjacent to first slit 50 with first slit 50 positioned between second slit 76 and fourth slit 90.
- Fourth slit 90 extends through second opposing end 80 of caul plate 46 toward end 78 of caul plate 46. End 92 of fourth slit 90 is defined by caul plate 46 positioned spaced apart from end 78 of caul plate 46.
- first, second, third and fourth slits 50, 76, 86 and 90 respectively are positioned in a locale of first curvature 28 of ramp 26 positioned within composite skin 20.
- distortion of fibers 34 and 36 within flange 30 and web 32 occur as a result of conforming blade stringer 24 to the contour of inner surface 22 of composite skin 20 prior to curing blade stinger 24.
- the fabricator can position slits and the size of the slits to provide controlled wrinkling in a composite part such as blade stringer 24, such that controlled wrinkling will comply with engineering and regulatory standards for fabrication of such part.
- first, second, third and fourth slits 50, 76, 86 and 90 The location of and dimension of slits such as first, second, third and fourth slits 50, 76, 86 and 90 by the fabricator will result, for example, in portion 94 of uncured composite material 48 to be pulled into first slit 50 and portion 96 of uncured composite material 48 to be pulled into third slit 86, as seen in FIG. 7 .
- the pulling of uncured composite material 48 occurs with vacuum bagging uncured composite material 48 and caul plate 46 and with the application of reduced air pressure being placed within the vacuum bagging.
- Uncured composite material 48 of blade stringer 24 is pulled into first and third slits 50, 86 along flange 30 and at the same time along first and third slits 50, 86 (not shown) along web 32 of blade stringer 24.
- uncured composite material 48 is also pulled into second and fourth slits 76, 90 along flange 30 and web 32.
- uncured composite material 48 pulled within first, second, third and fourth slits 50, 76, 86 and 90, respectively and cured the fabricator has produced wrinkles A, B, C and D of predetermined size and location, as seen in FIG. 8 , which correspond to position of first, second, third and fourth slits 50, 76, 86 and 90, respectively of caul plate 46 as seen in FIG. 6 .
- the control of the size and location of the wrinkling provides the fabricator an opportunity to optimize the production of a composite part such as blade stringer 24 so as to comply with the engineering specifications and regulatory guidelines for the amount of permitted wrinkling within the fabricated composite part.
- method 98 for fabricating a part is shown, such as for example blade stringer 24, constructed from uncured composite material 48, wherein the uncured composite material 48 has a geometric change, such as first curvature 28 of composite skin 20 which imparts a curvature in uncured composite material 48.
- Method 98 includes a step of positioning caul plate 46 in overlying relationship to uncured composite material 48.
- Uncured composite material 48 has a geometric change and caul plate 46 includes first slit 50 defined by and which extends through and along caul plate 46.
- Method 98 further includes placing uncured composite material 48 and caul plate 46 into a vacuum bagging (not shown).
- Method 98 further includes placing a reduced air pressure within the vacuum bagging (not shown) pulling a portion 94 of uncured composite material 48 into first slit 50.
- method 98 further includes heating uncured composite material 48 in an autoclave, for example, curing uncured composite material 48 and portion 94 of the uncured composite material 48 positioned within first slit 50 forming predetermined and controlled wrinkle A within cured composite material 48'as seen in FIGS. 7 and 8 .
- First slit 50 of caul plate 46 extends from surface 52 of caul plate 46, for positioning in facing relationship to surface 54 of uncured composite material 48, and extends through a thickness dimension of caul plate 46 to an opposing surface 56 of caul plate 46, for positioning in facing relationship away from surface 54 of uncured composite material 48.
- Caul plate 46 further includes second slit 76 defined by and which extends through and along caul plate 46 positioned spaced apart from first slit 50.
- First slit 50 and second slit 76 extend along caul plate 46 spaced apart from one another extending in same direction, as shown for example in FIG. 4 parallel to one another.
- First and second slits 50, 76 can be used to form predetermined controlled wrinkles A and B as shown in FIG. 8 . Additional slits can be provided as needed to produce permitted controlled wrinkling within the composite part which will comply with engineering specifications and regulatory guidelines.
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- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Chemical & Material Sciences (AREA)
- Composite Materials (AREA)
- Aviation & Aerospace Engineering (AREA)
- Moulding By Coating Moulds (AREA)
- Casting Or Compression Moulding Of Plastics Or The Like (AREA)
Abstract
Description
- This disclosure relates to fabrication of composite parts, and more particularly to controlling wrinkling in a finished composite part which incurred fiber distortion prior to curing.
- In fabrication of composite parts compressive strength of a finished composite part is known to be sensitive to the straightness of the fibers within the finished cured composite part. With the presence of waviness of fibers within the composite part, significant loss can be experienced in the strength of the composite part.
- An alteration or distortion of fiber straightness can occur in a number of different ways with respect to a composite part prior to curing. Examples of distortion of fibers prior to curing can occur with the composite part experiencing a change in geometry such as the uncured composite part being positioned to extend about a radius of curvature or with the uncured composite part having a ply drop. Regardless of the cause of imparting a change of direction of the fibers within the composite part being fabricated, the change of direction of the composite part can impart tension to fibers in a portion of the composite part and can impart compression to another portion of the composite part prior to curing. With fibers positioned in compression within the uncured composite part, the fibers can be distorted from a straight line alignment and experience bunching of the fibers. With the fibers in a distorted condition, curing of the composite part can result in uncontrolled wrinkling to occur in the cured composite part.
- Wrinkles which appear in a cured composite part can identify locations within the composite part where the fibers have been distorted and where the composite part has diminished strength. As a result, the fabricator can add additional composite material to the composite part to reinforce the composite part at those wrinkled locations so as to provide additional strength to the composite part. This procedure of adding composite material adds time, labor and material cost in fabricating the composite part. In addition, this procedure of adding composite material adds weight to the finished composite part. Adding weight to the finished composite part, that is used for example in fabricating an aircraft, contributes to additional cost of operation of the aircraft.
- In some instances of uncontrolled wrinkling occurring in the cured composite part, engineering specifications and/or other fabrication regulations, which limit the length and depth of permitted wrinkles in a finished composite part can be exceeded rendering the finished composite part unusable and resulting in the composite part being discarded. As a result, there is a need to control wrinkling which results from fibers being placed in compression condition and are distorted from straight-lined alignment incurred for example with uncured composite material experiencing geometry changes. The control of wrinkling of the finished composite part can avoid the need to add composite material to reinforce the strength of the composite part, which can add weight to a structure being fabricated with the composite part such as an aircraft, resulting in additional operational cost and/or can avoid uncontrolled wrinkling in the composite part exceeding engineering specifications and/or regulatory guidelines and being discarded.
- An example includes a caul plate for application onto an uncured composite material which includes a first slit defined by and which extends through and along the caul plate.
- An example includes a method for fabricating a part constructed from an uncured composite material having a geometric change within the uncured composite material, including a step of positioning a caul plate in overlying relationship to the uncured composite material having a geometric change in the uncured composite material, wherein the caul plate includes a first slit defined by and which extends through and along the caul plate.
- The features, functions, and advantages that have been discussed can be achieved independently in various examples or may be combined in yet other example further details of which can be seen with reference to the following description and drawings.
- Further, the disclosure comprises the following clauses:
- Clause 1. A caul plate (46) for application onto an uncured composite material (48), comprising:
a first slit (50) is defined by and which extends through and along the caul plate (46). -
Clause 2. The caul plate (46) of clause 1, wherein:- the first slit (50) extends through the caul plate (46) from a surface (52) of the caul plate (46), for positioning onto a surface (54) of the uncured composite material (48); and
- the first slit (50) extends through the caul plate (46) to an opposing surface (56) of the caul plate, for positioning in facing away relationship from the surface (54) of the uncured composite material (48) with the surface (52) of the caul plate (46) positioned onto the uncured composite material (48).
- Clause 3. The caul plate (46) of
clause 2, wherein at least a portion (58) of the surface (52) extends in a linear direction (Ld). - Clause 4. The caul plate (46) of
clause 2 or 3, wherein at least a portion (62) of the opposing surface (56) extends in a linear direction (Ld). - Clause 5. The caul plate (46) of clauses 2-4, wherein at least a portion (66) of the surface (52) extends in a curvilinear direction (C).
- Clause 6. The caul plate (46) of any of the clauses 2-5 , wherein at least a portion (68) of the opposing surface (56) extends in a curvilinear direction (C).
-
Clause 7. The caul plate (46) of clauses 1-6, wherein the first slit (50) extends in a linear direction (LD) along the caul plate (46). - Clause 8. The caul plate (46) of clauses 1-7, wherein a width dimension (W) of the first slit (50) includes a width dimension of 0.254mm (one hundredth of an inch (0.01 inch)) up to and including 1.27 mm (five hundreds of an inch (0.05 inch)).
- Clause 9. The caul plate (46) of clauses 1-8, wherein:
- the caul plate (46) includes a length (Lc); and
- the first slit (50) extends in a linear direction transverse to the length (Lc) of the caul plate (46).
-
Clause 10. The caul plate (46) of clauses 1-9, further including a second slit (76) defined by and which extends through and along the caul plate (46) positioned spaced apart from the first slit (50). - Clause 11. The caul plate (46) of
clause 10, wherein the first slit (50) and the second slit (76) extend along the caul plate (46) spaced apart from one another and extending in same direction. -
Clause 12. The caul plate (46) of any of the preceding clauses wherein the caul plate (46) includes an end (78) and a second opposing end (80). - Clause 13. The caul plate (46) of
clause 12, wherein:- the first slit (50) extends through the end (78) of the caul plate (46) and extends toward the second opposing end (80) of the caul plate (46) wherein an end (82) of the first slit (50) is defined by the caul plate (46) positioned spaced apart from the second opposing end (80) of the caul plate (46); and
- the second slit (76) extends through the second opposing end (80) of the caul plate (46) and extends toward the end (78) of the caul plate (46) wherein an end (84) of the second slit (76) is defined by the caul plate (46) positioned spaced apart from the end (78) of the caul plate (46).
-
Clause 14. The caul plate (46) of clause 13, further including:
a third slit (86) is defined by and which extends through and along the caul plate (46) positioned adjacent to the second slit (76) with the second slit (76) positioned between the first slit (50) and the third slit (86), wherein:- the third slit (86) extends through the end (78) of the caul plate (46) toward the second opposing end (80) of the caul plate (46); and
- an end (88) of the third slit (86) is defined by the caul plate (46) positioned spaced apart from the second opposing end (80) of the caul plate (46); and
- a fourth slit (90) is defined by and which extends through and along the caul plate (46) positioned adjacent to the first slit (50) with the first slit (50) positioned between the second slit (76) and the fourth slit (90), wherein:
the fourth slit (90) extends through the second opposing end (80) of the caul plate (46) toward the end (78) of the caul plate (46); and
- Clause 15. A method (98) for fabricating a part constructed from an uncured composite material (48) having a geometric change within the uncured composite material (48), comprising a step of positioning a caul plate (46) in overlying relationship to the uncured composite material (48) having a geometric change in the uncured composite material (48), wherein the caul plate (46) includes a first slit (50) defined by and which extends through and along the caul plate (46).
-
Clause 16. The method (98) of clause 15, further including placing the uncured composite material (48) and the caul plate (46) into a vacuum bag. - Clause 17. The method (98) of
clause 16, further including placing a reduced air pressure within the vacuum bag pulling a portion (94) of the uncured composite material (48) into the first slit (50). -
Clause 18. The method (98) of clause 17, further including heating the uncured composite material (48) and curing the uncured composite material (48) and the portion (94) of the uncured composite material (48) positioned within the first slit (50) forming a wrinkle (A) of cured composite material (48'). - Clause 19. The method (98) of clauses 15-18, wherein the first slit (50) of the caul plate (46) extends from a surface (52) of the caul plate (46), for positioning in facing relationship to a surface (54) of the uncured composite material (48), and extends through a thickness dimension of the caul plate (46) to an opposing surface (56) of the caul plate (46), for positioning in facing relationship away from the surface (54) of the uncured composite material (48).
-
Clause 20. The method (98) of clauses 15-19, wherein:- the caul plate (46) further includes a second slit (76) defined by and which extends through and along the caul plate (46) positioned spaced apart from the first slit (50); and
- the first slit (50) and the second slit (76) extend along the caul plate (46) spaced apart from one another extending in same direction.
-
-
FIG. 1 is perspective view of an aircraft; -
FIG. 2 is a schematic cross section view of a wing constructed of a composite skin and composite blade stringers as seen along line 2-2 ofFIG. 1 ; -
FIG. 3 is a perspective view of an uncured composite blade stringer extending along the composite skin of the wing ofFIG. 2 ; -
FIG. 4 is a partial perspective view of a portion of a caul plate used in fabrication of the blade stringer ofFIG. 3 ; -
FIG. 5 is a perspective view of the caul plate ofFIG. 4 positioned on the uncured blade stringer extending along the composite skin of the wing ofFIG. 3 ; -
FIG. 6 is a partial side elevation view of the caul plate ofFIG. 4 positioned on the uncured blade stringer ofFIG. 5 ; -
FIG. 7 is a partial enlarged side elevation view of the caul plate ofFIG. 6 with a reduced pressure having been applied to an outer surface of the caul plate -
FIG. 8 is a partial perspective view of the blade stringer ofFIG. 7 with the caul plate removed from the blade stringer after curing of the composite material and with controlled wrinkles positioned in the blade stringer; and -
FIG. 9 is a flow chart of method to cure a composite part having a geometric change. - Various parts used in the assembly of structures are constructed of composite material, which includes fibers and resin. In fabrication of the various parts, the parts are often subjected to alteration of geometric shape prior to being cured. The change in geometric shape of the uncured part results in distortion of straight-lined alignment of the reinforcement fibers within the composite material used in fabricating the part. The distortion of the straight-lined alignment of the fibers can occur by way of, for example, dropping of one or more plies in the construction of the composite part or by way of altering the shape of the composite part so as to conform to a shape of another part, such that the composite material is taken out of being positioned in a flat plane. Changing the shape of uncured composite material being used in constructing the part, by way of example of dropping plies and/or altering the shape of the composite material out of a flat configuration, alters or distorts the straight-lined alignment of the fibers within the uncured composite material from a straight lined orientation.
- For example, when fabricating a composite part, which includes the composite material being shaped to follow a curvature of an adjacent part, prior to curing, the fibers in a portion of the composite material which follows the curvature can become distorted from a straight-lined alignment. As the composite material follows the curvature, a portion of the fibers within the composite material can be placed in tension and another portion of the fibers within the composite material can be placed in compression. The fibers subjected to compression can become distorted and tend to bunch. In curing the composite material with bunched fibers, the cured composite part can develop undesired uncontrolled wrinkles. Should the uncontrolled wrinkling, which is indicative of reduced strength for the finished composite part, exceed engineering specifications and/or regulatory guidelines for wrinkling, additional composite material may need to be added to the part being fabricated or the part may need to be discarded.
- In referring to
FIGS. 1 - 3 ,aircraft 10 is an example of a structure having portions of the structure assembled with parts constructed of composite material, wherein the composite parts are subjected to geometric shape change prior to the composite part being cured. Examples of portions ofaircraft 10, which have composite parts which are subjected to geometric shape change prior to being cured include, for example,wings 12,fuselage 14,tail stabilizer 16,tail wings 18 as well as other structural portions ofaircraft 10 and as well as other portions of other structures which are assembled utilizing composite parts. - An example of a composite part subjected to geometric shape change prior to the composite part being cured is a stringer or stiffener which will be employed for example within
wing 12 ofaircraft 10.Wing 12 includescomposite skin 20 which has aninner surface 22, as seen inFIG. 3 , which has a contour which requiresblade stringer 24 constructed ofcomposite material 48 to change geometry or shape so as to conform toinner surface 22 ofcomposite skin 20.Blade stringer 24 conforms toinner surface 22 ofcomposite skin 20 so as to optimize securement ofblade stringer 24 tocomposite skin 20 and to optimize stiffening support ofblade stringer 24 tocomposite skin 20.Blade stringer 24 is described herein as an example of a composite part being fabricated wherein the geometry or shape of the composite part is changed prior to curing. Many other configurations of stringers or other composite parts can used so as to describe the teachings of this disclosure. -
Inner surface 22 ofcomposite skin 20 changes elevation or contour ofinner surface 22 ofcomposite skin 20 such as withramp 26 which includesfirst curvature 28 andsecond curvature 29. First andsecond curvatures ramp 26 incomposite skin 20. The contour or change in elevation ofinner surface 22 ofcomposite skin 20 can occur, for example, with ply drops incomposite skin 20 in accommodating load demands onwing 12 and/or for accommodating size ofwing 12, aswing 12 extends away fromfuselage 14. In order forblade stringer 24 to conform toinner surface 22 ofcomposite skin 20, the shape ofblade stringer 24 is altered prior to cure ofblade stringer 24 such thatflanges 30 andweb 32 ofblade stringer 24 follow the contour or curvature ofinner surface 22 ofcomposite skin 20 asblade stringer 24 extends alongramp 26. - In referring to
FIG. 6 , ramp 26 ofcomposite skin 20 is seen withfirst curvature 28 andsecond curvature 29 ofcomposite skin 20 positioned at opposing ends oframp 26, as mentioned above.Flange 30, ofblade stringer 24 shown inFIG. 3 , underliescaul plate 46 inFIG. 6 , includes uncuredcomposite material 48 which hasfibers 34 which extend along length L ofblade stringer 24, as seen inFIGS. 3 and6 .Web 32 ofblade stringer 24, includes uncuredcomposite material 48 which hasfibers 36 which also extend along length L ofblade stringer 24. With respect tofirst curvature 28 oframp 26 ofcomposite skin 20,upper portion 38 offibers 34 inflange 30 are placed in tension extending alongfirst curvature 28 andlower portion 40 offibers 34 inflange 30 are placed in compression extending alongfirst curvature 28. Atfirst curvature 28fibers 36 withinweb 32, which also extend along length L ofblade stringer 24, extend alongfirst curvature 28 ofcomposite skin 20 withupper portion 42 offibers 36 inweb 32 placed in tension and with lower portion 44 offibers 36 inweb 32 placed in compression. - At
second curvature 29 oframp 26 positioned incomposite skin 20,fibers 34 of uncuredcomposite material 48 offlange 30 ofblade stringer 24 hasupper portion 38 offibers 34 inflange 30 placed in compression, which extends alongsecond curvature 29, andlower portion 40 offibers 34 inflange 30 placed in compression, which extends alongsecond curvature 29.Fibers 36 withinweb 32 which extend alongsecond curvature 29 hasupper portion 42 offibers 36 inweb 32 placed in compression and lower portion 44 offibers 36 inweb 32 placed in compression. - As a result, with respect to
first curvature 28 ofcomposite skin 20,lower portion 40 offibers 34 offlange 30 and lower portion 44 offibers 36 ofweb 32 are positioned in compression resulting in distortion infibers 34, inlower portion 40 offlange 30 and infibers 36 in lower portion 44 ofweb 32 from straight-lined alignment. Similarly, with respect tosecond curvature 29 ofcomposite skin 20,upper portion 38 offibers 34 offlange 30 andupper portion 42 offibers 36 ofweb 32 are positioned in compression resulting infibers 34 withinupper portion 38 offlange 30 andfibers 36 inupper portion 42 being distorted from straight-lined alignment. Without any mitigating efforts taken, the curing ofblade stringer 24, the distorted fibers would cause uncontrolled wrinkling in the curedblade stringer 24. However with application ofcaul plate 46, as seen inFIGS. 4-6 , touncured blade stringer 24 along with an application of reduced air pressure with placing uncuredcomposite material 48 andcaul plate 46 in vacuum bagging (not shown) during the curing process, provides the fabricator with the ability to control wrinkling in the finished curedblade stringer 24, as will be discussed in more detail herein. Controlled wrinkling in thefinished blade stringer 24 optimizes use of the finished composite part withblade stringer 24 conforming to the engineering specifications and regulatory guidelines related to amount and size of permitted wrinkling that is permitted in a finished composite part and also optimizes resulting strength ofblade stringer 24. -
Caul plate 46, as seen inFIGS. 4-6 , is positioned onto uncuredcomposite material 48, as seen inFIGS. 3 and5 , which includes uncuredcomposite material 48 offlange 30 andweb 32 ofblade stringer 24 in this example for utilization in the curing process ofblade stringer 24. Withcaul plate 46 positioned on uncuredcomposite material 48 of a part to be cured, such asblade stringer 24,caul plate 46 and uncuredcomposite material 48, are placed within a vacuum bagging (not shown) and a reduced pressure is applied within the vacuum bagging, as mentioned above, pulling fibers and resin from uncuredcomposite material 48 into slits ofcaul plate 46 as will be described below. Heat is also applied in the curing process curing uncuredcomposite material 48 resulting in controlled wrinkle(s) being positioned inblade stringer 24 formed from fiber and resin material of the uncuredcomposite material 48 pulled into slit(s) of . In this example, twocaul plates 46 are used in constructingblade stringer 24 wherein eachcaul plate 46 has a L-shaped configuration and is positioned on opposing sides of uncuredcomposite material 48 ofblade stringer 24, as seen inFIG. 5 . Other shapes of caul plate(s) 46 can be used for accommodating other shapes of stringers or for other composite parts being fabricated, which have a geometric change of shape distorting fibers from a straight-lined alignment in forming composite parts prior to curing. - In referring to
FIGS. 4-6 ,caul plate 46 is used in placing onto uncuredcomposite material 48 for use during the curing process of uncuredcomposite material 48 fabricating a composite part such asblade stringer 24 with controlled wrinkling.Caul plate 46 includes first slit 50 defined by and which extends through and alongcaul plate 46. First slit 50 extends throughcaul plate 46 fromsurface 52 ofcaul plate 46, for positioning ontosurface 54 of uncuredcomposite material 48. First slit 50 extends throughcaul plate 46 to an opposingsurface 56 ofcaul plate 46, for positioning in facing relationship away fromsurface 54 of uncuredcomposite material 48, as seen for example inFIG. 5 , withsurface 52 ofcaul plate 46 positioned onto uncuredcomposite material 48. - In referring to
FIGS. 4 and5 , at least aportion 58 ofsurface 52, ofcaul plate 46, which is positioned onto uncuredcomposite material 48 offlange 30 extends in a linear direction L as seen inFIG. 5 . Similarly, at least aportion 60 ofsurface 52 ofcaul plate 46 which is positioned onto uncuredcomposite material 48 ofweb 32 extends in linear direction L', as seen inFIG. 5 . At least aportion 62 of opposingsurface 56 ofcaul plate 46 which is positioned facing away fromcomposite material 48 offlange 30 extends in linear direction L, as seen inFIG. 5 , and at least aportion 64 of opposingsurface 56 ofcaul plate 46 is positioned facing away from uncuredcomposite material 48 ofweb 32 extends in linear direction L', as also seen inFIG. 5 . At least aportion 66 ofsurface 52 extends in a curvilinear direction C and aportion 68 of opposingsurface 56 extends in the curvilinear direction C. - In referring to
FIGS. 4 and5 , first slit 50 extends in a linear direction LD alongportion 70 ofcaul plate 46 which extends in this example alongflange 30 ofblade stringer 24 and extends in a linear direction LD' alongportion 72 ofcaul plate 46, which extends in this example alongweb 32 ofblade stringer 24. In this example, with respect tocaul plate 46 being used for formingblade stringer 24,portions caul plate 46 join one another along acurved portion 74 ofcaul plate 46 as seen inFIG.4 . First slit 50 extends throughcaul plate 46 positioned withinportions caul plate 46 and withincurved portion 74 ofcaul plate 46, as also seen inFIG. 4 . - First slit 50 can be made in a variety of width dimensions and length dimensions as needed for forming controlled wrinkles within a composite part being fabricated. In this example, width dimension W includes for example one hundredth of an inch (0.01 inch) up to and including five hundreds of an inch (0.05 inch).
Caul plate 46 includes length L andfirst slit 50 extends in linear direction LD alongportion 70 ofcaul plate 46, for positioning onto uncuredcomposite material 48 forflange 30 ofblade stringer 24, extending in a transverse direction relative to length L ofcaul plate 46 as seen inFIG. 4 . Similarly, first slit 50 extends in linear direction LD' alongportion 72 ofcaul plate 46, for positioning onto uncuredcomposite material 48 forweb 32 ofblade stringer 24, extending in a transverse direction relative to length L ofcaul plate 46 as also seen inFIG. 4 . - As seen in
FIGS 4 and6 caul plate 46 further includessecond slit 76 defined by and which extends through and alongcaul plate 46 positioned spaced apart fromfirst slit 50. First slit 50 and second slit 76 extend alongcaul plate 46 spaced apart from one another and extending in the same direction, and as shown inFIG. 4 , parallel to one another.Caul plate 46 includesend 78 and second opposingend 80. First slit 50 extends throughend 78 ofcaul plate 46 and extends toward second opposingend 80 ofcaul plate 46 whereinend 82 offirst slit 50 is defined bycaul plate 46 positioned spaced apart from second opposingend 80 ofcaul plate 46. Second slit 76 extends through second opposingend 80 ofcaul plate 46 and extends towardend 78 ofcaul plate 46 whereinend 84 ofsecond slit 76 is defined bycaul plate 46 positioned spaced apart fromend 78 ofcaul plate 46. - In further referring to
caul plate 46 ofFIG. 4 ,third slit 86 is defined by and extends through and alongcaul plate 46 is positioned adjacent tosecond slit 76 withsecond slit 76 positioned betweenfirst slit 50 andthird slit 86. Third slit 86 extends throughend 78 ofcaul plate 46 toward second opposingend 80 ofcaul plate 46.End 88 ofthird slit 86 is defined bycaul plate 46 positioned spaced apart from second opposingend 80 ofcaul plate 46. Fourth slit 90 is defined by and extends through and alongcaul plate 46 positioned adjacent tofirst slit 50 withfirst slit 50 positioned betweensecond slit 76 andfourth slit 90. Fourth slit 90 extends through second opposingend 80 ofcaul plate 46 towardend 78 ofcaul plate 46.End 92 offourth slit 90 is defined bycaul plate 46 positioned spaced apart fromend 78 ofcaul plate 46. The configuration of ends, 82, 84, 88 and 92 of first, second and third andfourth slits caul plate 46 to extend along length L ofblade stringer 24 without the need to breakcaul plate 46 into separate pieces. - The configuration of first, second, third and
fourth slits first curvature 28 oframp 26 positioned withincomposite skin 20. As earlier discussed, distortion offibers flange 30 andweb 32 occur as a result of conformingblade stringer 24 to the contour ofinner surface 22 ofcomposite skin 20 prior to curingblade stinger 24. The fabricator can position slits and the size of the slits to provide controlled wrinkling in a composite part such asblade stringer 24, such that controlled wrinkling will comply with engineering and regulatory standards for fabrication of such part. The location of and dimension of slits such as first, second, third andfourth slits portion 94 of uncuredcomposite material 48 to be pulled intofirst slit 50 andportion 96 of uncuredcomposite material 48 to be pulled intothird slit 86, as seen inFIG. 7 . The pulling of uncuredcomposite material 48 occurs with vacuum bagging uncuredcomposite material 48 andcaul plate 46 and with the application of reduced air pressure being placed within the vacuum bagging. Uncuredcomposite material 48 ofblade stringer 24 is pulled into first andthird slits flange 30 and at the same time along first andthird slits 50, 86 (not shown) alongweb 32 ofblade stringer 24. Similarly, (not shown) uncuredcomposite material 48 is also pulled into second andfourth slits flange 30 andweb 32. With uncuredcomposite material 48 pulled within first, second, third andfourth slits FIG. 8 , which correspond to position of first, second, third andfourth slits caul plate 46 as seen inFIG. 6 . The control of the size and location of the wrinkling provides the fabricator an opportunity to optimize the production of a composite part such asblade stringer 24 so as to comply with the engineering specifications and regulatory guidelines for the amount of permitted wrinkling within the fabricated composite part. - In referring to
FIG. 9 ,method 98 for fabricating a part is shown, such as forexample blade stringer 24, constructed from uncuredcomposite material 48, wherein the uncuredcomposite material 48 has a geometric change, such asfirst curvature 28 ofcomposite skin 20 which imparts a curvature in uncuredcomposite material 48.Method 98 includes a step of positioningcaul plate 46 in overlying relationship to uncuredcomposite material 48. Uncuredcomposite material 48 has a geometric change andcaul plate 46 includes first slit 50 defined by and which extends through and alongcaul plate 46.Method 98 further includes placing uncuredcomposite material 48 andcaul plate 46 into a vacuum bagging (not shown). -
Method 98 further includes placing a reduced air pressure within the vacuum bagging (not shown) pulling aportion 94 of uncuredcomposite material 48 intofirst slit 50. In addition,method 98 further includes heating uncuredcomposite material 48 in an autoclave, for example, curing uncuredcomposite material 48 andportion 94 of the uncuredcomposite material 48 positioned withinfirst slit 50 forming predetermined and controlled wrinkle A within cured composite material 48'as seen inFIGS. 7 and8 . - First slit 50 of
caul plate 46 extends fromsurface 52 ofcaul plate 46, for positioning in facing relationship to surface 54 of uncuredcomposite material 48, and extends through a thickness dimension ofcaul plate 46 to an opposingsurface 56 ofcaul plate 46, for positioning in facing relationship away fromsurface 54 of uncuredcomposite material 48.Caul plate 46 further includessecond slit 76 defined by and which extends through and alongcaul plate 46 positioned spaced apart fromfirst slit 50. First slit 50 and second slit 76 extend alongcaul plate 46 spaced apart from one another extending in same direction, as shown for example inFIG. 4 parallel to one another. First andsecond slits FIG. 8 . Additional slits can be provided as needed to produce permitted controlled wrinkling within the composite part which will comply with engineering specifications and regulatory guidelines.
Claims (15)
- A caul plate (46) for application onto an uncured composite material (48), comprising:
a first slit (50) is defined by and which extends through and along the caul plate (46). - The caul plate (46) of claim 1, wherein:the first slit (50) extends through the caul plate (46) from a surface (52) of the caul plate (46), for positioning onto a surface (54) of the uncured composite material (48); andthe first slit (50) extends through the caul plate (46) to an opposing surface (56) of the caul plate, for positioning in facing away relationship from the surface (54) of the uncured composite material (48) with the surface (52) of the caul plate (46) positioned onto the uncured composite material (48).
- The caul plate (46) of claim 2, wherein at least a portion (58) of the surface (52) extends in a linear direction (Ld) optionally,
wherein at least a portion (62) of the opposing surface (56) extends in a linear direction (Ld). - The caul plate (46) of claims 2-3, wherein at least a portion (66) of the surface (52) extends in a curvilinear direction (C) optionally,
wherein at least a portion (68) of the opposing surface (56) extends in a curvilinear direction (C). - The caul plate (46) of claims 1-4, wherein the first slit (50) extends in a linear direction (LD) along the caul plate (46).
- The caul plate (46) of claims 1-5, wherein a width dimension (W) of the first slit (50) includes a width dimension of 0.254mm (one hundredth of an inch (0.01 inch)) up to and including 1.27 mm (five hundreds of an inch (0.05 inch)).
- The caul plate (46) of claims 1-6, wherein:the caul plate (46) includes a length (Lc); andthe first slit (50) extends in a linear direction transverse to the length (Lc) of the caul plate (46).
- The caul plate (46) of claims 1-7, further including a second slit (76) defined by and which extends through and along the caul plate (46) positioned spaced apart from the first slit (50) optionally,
wherein the first slit (50) and the second slit (76) extend along the caul plate (46) spaced apart from one another and extending in same direction. - The caul plate (46) of claim 8, wherein the caul plate (46) includes an end (78) and a second opposing end (80) optionally,
wherein:the first slit (50) extends through the end (78) of the caul plate (46) and extends toward the second opposing end (80) of the caul plate (46) wherein an end (82) of the first slit (50) is defined by the caul plate (46) positioned spaced apart from the second opposing end (80) of the caul plate (46); andthe second slit (76) extends through the second opposing end (80) of the caul plate (46) and extends toward the end (78) of the caul plate (46) wherein an end (84) of the second slit (76) is defined by the caul plate (46) positioned spaced apart from the end (78) of the caul plate (46). - The caul plate (46) of claim 9, further including:a third slit (86) is defined by and which extends through and along the caul plate (46) positioned adjacent to the second slit (76) with the second slit (76) positioned between the first slit (50) and the third slit (86), wherein:the third slit (86) extends through the end (78) of the caul plate (46) toward the second opposing end (80) of the caul plate (46); andan end (88) of the third slit (86) is defined by the caul plate (46) positioned spaced apart from the second opposing end (80) of the caul plate (46); anda fourth slit (90) is defined by and which extends through and along the caul plate (46) positioned adjacent to the first slit (50) with the first slit (50) positioned between the second slit (76) and the fourth slit (90), wherein:the fourth slit (90) extends through the second opposing end (80) of the caul plate (46) toward the end (78) of the caul plate (46); andan end (92) of the fourth slit (90) is defined by the caul plate (46) positioned spaced apart from the end (78) of the caul plate (46).
- A method (98) for fabricating a part constructed from an uncured composite material (48) having a geometric change within the uncured composite material (48), comprising a step of positioning a caul plate (46) in overlying relationship to the uncured composite material (48) having a geometric change in the uncured composite material (48), wherein the caul plate (46) includes a first slit (50) defined by and which extends through and along the caul plate (46).
- The method (98) of claim 11, further including placing the uncured composite material (48) and the caul plate (46) into a vacuum bag optionally,
further including placing a reduced air pressure within the vacuum bag pulling a portion (94) of the uncured composite material (48) into the first slit (50). - The method (98) of claim 12, further including heating the uncured composite material (48) and curing the uncured composite material (48) and the portion (94) of the uncured composite material (48) positioned within the first slit (50) forming a wrinkle (A) of cured composite material (48').
- The method (98) of claims 11-13, wherein the first slit (50) of the caul plate (46) extends from a surface (52) of the caul plate (46), for positioning in facing relationship to a surface (54) of the uncured composite material (48), and extends through a thickness dimension of the caul plate (46) to an opposing surface (56) of the caul plate (46), for positioning in facing relationship away from the surface (54) of the uncured composite material (48).
- The method (98) of claims 11-14, wherein:the caul plate (46) further includes a second slit (76) defined by and which extends through and along the caul plate (46) positioned spaced apart from the first slit (50); andthe first slit (50) and the second slit (76) extend along the caul plate (46) spaced apart from one another extending in same direction.
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US16/269,614 US20200254702A1 (en) | 2019-02-07 | 2019-02-07 | Apparatus and method to tailor fiber distortion in composite parts |
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Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
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EP3970938A1 (en) * | 2020-09-17 | 2022-03-23 | The Boeing Company | Tool and method for forming contoured composite stringers having reduced wrinkling |
EP4197771A1 (en) * | 2021-12-14 | 2023-06-21 | The Boeing Company | Wrinkle mitigation in contoured composite stiffeners |
US11806947B2 (en) | 2021-01-29 | 2023-11-07 | The Boeing Company | Forming system and method for forming a contoured composite structure |
Families Citing this family (1)
Publication number | Priority date | Publication date | Assignee | Title |
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US11554559B2 (en) * | 2019-12-11 | 2023-01-17 | The Boeing Company | Caul plate for irregular surface |
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US20120168071A1 (en) * | 2011-01-03 | 2012-07-05 | The Boeing Company | Method and device for compressing a composite radius |
US20140314996A1 (en) * | 2013-04-19 | 2014-10-23 | The Boeing Company | Compacting Uncured Composite Members on Contoured Mandrel Surfaces |
EP3162544A1 (en) * | 2015-10-06 | 2017-05-03 | The Boeing Company | Method and device for producing contoured composite laminate stiffeners with reduced wrinkling |
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US9278484B2 (en) | 2008-04-17 | 2016-03-08 | The Boeing Company | Method and apparatus for producing contoured composite structures and structures produced thereby |
US10808091B2 (en) | 2014-09-19 | 2020-10-20 | Toray Industries, Inc. | Notched pre-preg and notched pre-preg sheet |
US10392132B2 (en) | 2016-07-29 | 2019-08-27 | The Boeing Company | Curved aircraft substructure repair systems and methods |
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2019
- 2019-02-07 US US16/269,614 patent/US20200254702A1/en not_active Abandoned
- 2019-12-10 CA CA3064841A patent/CA3064841A1/en active Pending
- 2019-12-12 JP JP2019224633A patent/JP7469034B2/en active Active
- 2019-12-18 EP EP19217732.7A patent/EP3693155B1/en active Active
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2020
- 2020-01-02 AU AU2020200004A patent/AU2020200004A1/en active Pending
- 2020-01-13 BR BR102020000707-6A patent/BR102020000707A2/en active IP Right Grant
- 2020-02-05 CN CN202010080661.5A patent/CN111531924B/en active Active
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2022
- 2022-07-25 US US17/872,282 patent/US11993033B2/en active Active
Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
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US20120168071A1 (en) * | 2011-01-03 | 2012-07-05 | The Boeing Company | Method and device for compressing a composite radius |
US20140314996A1 (en) * | 2013-04-19 | 2014-10-23 | The Boeing Company | Compacting Uncured Composite Members on Contoured Mandrel Surfaces |
EP3162544A1 (en) * | 2015-10-06 | 2017-05-03 | The Boeing Company | Method and device for producing contoured composite laminate stiffeners with reduced wrinkling |
Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
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EP3970938A1 (en) * | 2020-09-17 | 2022-03-23 | The Boeing Company | Tool and method for forming contoured composite stringers having reduced wrinkling |
US11760040B2 (en) | 2020-09-17 | 2023-09-19 | The Boeing Company | Tool and method for forming contoured composite stringers having reduced wrinkling |
US11806947B2 (en) | 2021-01-29 | 2023-11-07 | The Boeing Company | Forming system and method for forming a contoured composite structure |
EP4197771A1 (en) * | 2021-12-14 | 2023-06-21 | The Boeing Company | Wrinkle mitigation in contoured composite stiffeners |
US11806954B2 (en) | 2021-12-14 | 2023-11-07 | The Boeing Company | Wrinkle mitigation in contoured composite stiffeners |
Also Published As
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US20200254702A1 (en) | 2020-08-13 |
CN111531924B (en) | 2023-11-24 |
AU2020200004A1 (en) | 2020-08-27 |
CA3064841A1 (en) | 2020-08-07 |
EP3693155B1 (en) | 2024-01-31 |
US20220355556A1 (en) | 2022-11-10 |
BR102020000707A2 (en) | 2020-10-06 |
US11993033B2 (en) | 2024-05-28 |
JP7469034B2 (en) | 2024-04-16 |
CN111531924A (en) | 2020-08-14 |
JP2020128080A (en) | 2020-08-27 |
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